Esters of alcohol nontertiary amines



Patented Sept. 21, 1948 Frank J. Cahn, Chicago, 111., assignor to TheEmulsol Corporation, Chicago, 111., a corporation of Illinois NoDrawing. Application August 29, 1941,

. Serial No. 408,823

This invention relates to the preparation of carboxylic esters ofalcohol non-tertiary amines, particularly higher molecular weight fattyacid esters of hydroxy-alkyl primary and secondary amines.

It has heretofore been suggested, as disclosed, for example, in UnitedStates Patent No. 2,206,928, in United States Reissue Patent No. 21,530,and in British Patent No. 337,737, to prepare condensation products ofhigher molecular weight fatty acids with hydroxy-alkyl primary orsecondary amines or, in other words, hydroxyalkyl non-tertiary amines.Instead of employing the free higher molecular weight fatty acids in thecondensation reaction, the corresponding halides, anhydrides and estershave been suggested. In all of these cases, the resulting condensationproducts comprise mixtures of amides and relatively small proportions ofesters or mixed-ester amides of the hydroxy-alkyl nontertiary amines,the amides largely predominating where equi-molal ratios of higher fattyacid and hydroxy-alkyl primary amine are condensed, and the mixedester-amides largely predominating where an excess of higher fatty acidor the like is employed in the condensation reaction; and no way hasbeen found which is feasible for effecting a separation of therelatively small proportion of esters from the amides and mixedester-amides. Thus, for example, if monoethanolamine is condensed withan equi-molal amount of lauric acid at elevated temperatures, in excessof 100 degrees C. and particularly at the recommended temperatures of150 degrees C. to 1'75 degrees C., or with lauroyl chloride or esters oflauric acid, the resulting condensation products comprise predominantlythe lauric acid amide, and relatively small amounts of mixed ester-amideand lauric acid ester of monoethanolamine, which are inextricablymixedwith the amide. It has been found that, for certain purposes, thehigher molecular weight aliphatic carboxylic acid esters of thehydroxy-alkyl nontertiary amines, and more particularly the hydrohalidesalts of said esters, substantially free of the corresponding amides ormixed esteramides are necessary but,'to my knowledge, no one hasheretoforeproduced such products nor suggested any manner or method foraccomplishing such production. The products are not only different incomposition but there are also important distinctions in properties andfunctions in relation to the known condensation products disclosed inthe patents referred to hereinabove.

In accordance with the present invention, substantially quantitativeyields of hydrohalide salts of esters of hydroxy-alkyl non-tertiaryamines may be produced in a simple and efficacious manner, devoid'orsubstantially devoid of thecorresponding amides or mixed ester-amides.

In general, the novel process comprises reacting a carboxylic acid acylhalide, particularly a higher molecular weight aliphatic or fatty acylchloride, for example, lauroyl chloride, with an hydroxy-alkylnon-tertiary amine hydrohalide salt, for example, monoethanolaminehydrochloride, in the presence of an acidic catalyst such assulphoacetic acid or the like. and preferably at relatively lowtemperatures, that is, below 100 degrees C. The ester is recovered inthe form of a hydrohalide salt, in the particular illustration given, asthe hydrochloride of the lauric acid ester of monoethanolamine.

In order that those skilled in the art may readily and fully understandthe manner in which the invention may be practiced, various specificembodiments thereof are set out hereinbelow. It will be understoodthatthese are merely illustrative and are not to be construed as limitativeof the full scope of the invention in any way. Thus, for example,different combinations of reacting ingredients may be employed, changesmay be made in the proportions and temperatures of treatment, such asthe use of temperatures of about 50 degrees C. or 60 degrees C.

coupled with kneading or vigorous stirring. and other changes may bemade, such as the use of acyl bromides instead of acyl chlorides,without departing from the principles of the invention as set outhereinabove and in the appended claims:

Example I fatty acids and about 101.7%01' the theoretical chlorinecontent, thus showing that the product was quite pure. The productreadily dissolves in water to produce a substantially clear solutionboth in low and in high concentrations.

The coconut oil mixed fatty acid acyl chlorides, used in the example,were prepared in accordance with the method described in my copendingapplication, Serial No. 351,441, filed August 4, 1940, now Patent No.2,282,320, issued May 12, 1942. In accordance with that method, coconutoil mixed fatty acids or lauric acid or other higher molecularweight-aliphatic carboxylic acids are mixed with phosphorous trichloridein a mole] ratio oi about one mol of the carboxylic acid to preferablyabout 50% in excess of ,5 mol of phosphorous trichloride. The resultingmixture is heated slowly, while stirrin to about 60 degrees C. to 90degrees C., care being exercised to avoid local superheating. Thereaction mixture is then allowed to cool to about 40 degrees C. or 50'degrees C; and the lower layer of phosphorous acid is completely drawn011. The upper layer, containing the acyl chloride, is then subjected toa vacuum and a stream 01' an inert gas such as carbon dioxide is passedthrough the acyl halide while simultaneously heating at about 130degrees C. for about one-half hour. This results in removing excess orunreacted phosphorous trichloride and in insuring the preparation of apure acyl halide. By leaving a small proportion of phosphoroustrichloride, for example, about 0.1% to about 0.2%, in the acyl halideproduct, no extraneous catalyst such as sulphoacetic acid or the likeneed be employed, the phosphorous trichloride serving to catalyticallycondition the acyl halide for the reaction.

' The sulphoacetic acid used in the example was a crude reaction productobtained by mixing one mol of concentrated sulphuric acid with two moleof acetic anhydride. Pure sulphoacetic acid may be employed withsimilarly satisfactory results.

Example 11 17.7 grams of the hydrochloride of hydroxyethyl ethylenediamine HO-QHr-NH-Cdh-NEBCI were mixed with 22.0 grams of coconut oilmixed fatty acid acylchlorides and with 0.6 gram of sulphoacetic acid asa catalyst. The reaction set in at 80 degrees C. and became violent whenthe temperature was raised to 140 degrees C. The resulting homogeneousproduct consisted almost entirely of the hydrochloride or the coconutoil mixed fatty acid esters of hydroxyethyl ethylene diamine. Theproduct readily dissolves in water to produce a practically clearsolution which foams strongly even after acidulation. v

The hydrochloride of hydroxy-ethyl ethylene diamine was prepared byadding to 559 grams of concentrated hydrochloric acid 260 grams ofhydroxy-ethyl ethylene diamine previously dissolved in 260 cubiccentimeters of water. The mass was heated to about 180 degrees C. invacuo to evaporate the water. The viscous reaction product solidified atroom temperature'to a hard rocklike substance.

Example III (a) To 33.3 grams of diethanolamine hydrochloride there wereadded 25.3 grams of lauroyl ble in cold water.

of the lauric acid di -ester of diethanolamine hydrochloride. Theproduct was dispersible in hot water and foamed in neutral as well asacidulated water.

(b) 7.0 grams oi the waxy product of part (a) hereof were washed withcold water and then crystallized from 200 cc. of hot isopropyl alcohol.About 4.5 grams of a white crystalline material vwas obtained. 0nanalysis, its content of ionizable chlorine indicated that the productconsisted of substantially pure lauric acid diester of diethanolaminehydrochloride.

Example IV 30.4 grams of diethanolamine hydrochloride, 70.0 grams ofcaprylyl chloride and 0.3 cc. of phosphorous trichloride were mixedtogether and heated, with stirring. The reaction set in at about 70degrees C., with the evolution of hydrochloric acid, and wassubstantially complete at degrees C. within a, few minutes. The reactionmixture was then heated up to degrees C. 0n cooling to room temperature,a solid' waxy material was obtained in the form of an upper layer, asmall amount of unreacted diethanolamine hydrochloride remaining on thebottom oi. the reaction vessel. The waxy material, consisting mainly ofthe caprylic acid. diester of diethanolamine hydrochloride, was solu- Ifdesired, it may be purified by recrystallization from isopropyl alcohol,as described in Example III.

The alcohol primary and secondary amines, or hydroxy-alkyl primary andsecondary amines which, in the form 01 hydrohalide salts, are utilizedin making said salts of'the esters may be selected from a large group,including symmetrical, unsymmetrical, normal and iso-derivatives, suchas monoethanolamine, diethanolamine, monopropanolamine, dipropanolamine,monobutanolamine, mono-isobutanolamine, monopentanolamine,dibutanolamine, dipentanolamine, monoand di-hexanolamine, monoanddi-octanolamine, monoand di-decylolamine, mono-laurylolamine,mono-hexadecylolamine, mono-octadecylolamine, mono-ethyl ethanolamine,mono-butyl ethanolamine; arylolamines and cyclic hydroxy amines such ascyclohexyl ethanolamine, N-cyclohexyl butanolamine, ethanolaniline,phenylethanolamine, p-amino phenol,

no-om-Onm 2-methylamino-propan-dio1-1,3; l-phenylaminopropan-diol-2,3;1-hydroxy-ethylamino-2, methoxy-propan-dl-3;2-N-methylamino-propan-diol- 1,3; monoethanol monopropanolamine, mono orcommercial form;

sugar alcohols such as ethylene glycol, diethylene glycol, dextrose,sucrose, sorbitol, mannitol and dulcitol;

canton min-NB-OJLOH cim-o-crnron cim-o-cinron droxy stearic acid,alpha-hydroxy palmitic acid, alpha-hydroxy lauric acid, alpha-hydroxycoconut oil mixed fatty acids, and the like; fatty acids derived fromvarious waxes such as beeswax, spermaceti, montan wax, and carnauba waxand carboxylic acids derived, by oxidation and other methods, frompetroleum; cycloaliphatic and hydroaromatic acids such ashexahydrobenzoic acid, resinic acids, naphthenic acids 'and abieticacid; aromatic acids such as phthalic acid,-benzoic acid, naphthoicacid, pyridine carboxylic acids; hydroxy aromatic acids such assalicyclic acid, hydroxy benzoicand naphthoic .2-amino-2-ethylol-L3acids, and the like; and substitution and addition derivatives,particularly halogen substitution and addition derivatives of theaforementioned carboxylic substances. It will be understood that acylhalides of mixtures of any two or more of said acids may be employed ifdesired. The acyl chlorides of the unsubstituted fatty acids having fromeight to eighteen carbon atoms are especially satisfactory.

, The catalysts may be selected from a largegroup includingfor example,sulphoacetic acid,

hydrocarbons, substituting me'thylol groups for hydrogen on the carbonsto" which, the iiitro groupsare attached, and then reducing the nitro'groups to' amine groups'."'. These, amine groups I may befurtheralkylated or otherwise substituted if desired. Polymerized, hydroxynon-tertiary amines 0r polymerized'hydroxy amines contain-, ing hydrogendirectly attached to nitrogen. and

prepared, for example, by polymerizing monoetha'nolamine ordiethanolamine or mixtures. thereof, or other hydroxy-alkyl hon-tertiaryamines such as those mentioned hereinabove, particularly in the presenceof a catalyst such as'sodium hydroxide; or .the' like, may also be"employed. The preparation offpolymerized hydroxy amines-is disclosed,for example, in United. States Patent No. 2,178,173. Homologues and.

phosphorous acids, phosphorous trichloride, and the like.

Itwlli be understood that any of the hydrohalide salts'of any of thealcohol non-tertiary amines disclosed may be reacted with any of thedisclosed carboxylic acid acyl halides in the presence of any of thecatalysts.

In general, I prefer to carry out the esteriflcation reaction at atemperature ranging between about 70 degrees C. and 140 degrees C. atatmospheric pressure. It .will be understood, however,

that the reaction temperature may be varied and that the reaction may beconducted under subatmospheric or super-atmospheric pressures if sodesired.

The salts of many of the esters possess detergent and surfacemodlfyingproperties and characteristics. In general, they are not stable in thepresence of alkalies. For certain purposes, therefore, ity isadvantageous to admix or combine them with acid salts such as sodiumacid sulphate and the like or with neutral salts such as sodiumsulphate. They may, in general,

substitution derivatives oi the above-mentioned hydroxy amines may alsobe utilized. It will be understood that the hydroxy-alkyl primary andsecondar amines maybe utilized in "pure, impure The carboxylic acidswhose acyl used in the reaction with the alcohol primary or secondaryamines may also be selected from an extensive group including'straightchain and branched chain aliphatic (includin cycle-aliphatic) carboxyllcacids, saturated and unsatuhalides are rated, such as butyric acid,caprylic acidjc'aproic acid, capric acid, sebacic acid, -behenic .acid,arachidic acid, cerotic acid, erucic acid, melissic acid, stearicacid,oleic acid, ricinoleic acid,..linoleic acid, linolenic acid, lauricacid, myristic acid, palmitic' acid, mixtures of any two ormore of theabove-mentioned acids or other acids, mixed higherfatty acids derivedfrom animal or vegetable sources, for example, lard, coconut oil,rapeseed oil, sesame oil, palm kernel oil palm oil, olive oil, corn oil,cottonseed oil, sardine oil, tallow, soya bean oil, peanut oil, castoroil, seal oils, whale oil, shark oil, partiall'yor completelyhydrogenated animal and vegetable oils such as those mentioned; hydroxyand alpha hydroxy higher aliphatic and fatty acids such as i-hydroxystearic acid, dihydroxystearic acid, alpha-hybe employed for the usesand purposes for which surface or interface modifying agents have beensuggested in the prior art. Thus, for example, they may be utilized forthe softening of textiles such as cellulose esters and ethers, rayon,and natural and synthetic fibres. They are'especially useful in oreflotation operations, particularly for separating silica from manganeseores and other ores. Many of them possess bactericidal, bacteriostatic,germicidal and like properties which, together with their surfacemodifying characteristics, may be taken advantage of in dentifrices,cosmetic creams, shaving creams of the lathering and brushless type andthe like. They may be utilized in the presence of dilute acids such ashydrochloric acid, sulphuric acid, sulphurous acid, acetic acid, andsimilar inorganic and organic acids. They may also be employed in thepresence of such diverse substances as hydrophilic gums includingpectin, tragacanth, karaya, locust bean, gelatin, arable and the like,glue, vegetable,-animal, fish and mineral oils, solvents such as carbontetrachloride, monoethyl ether of ethylene glycol, monobutyl ether ofethylene glycol, monoethyl and monobutyl ethers of di- -ethylene glycol,cyclohexanol, higher fatty acid partial esters of aliphatic polyhydroxysubstances suchas mono-caprylin, mono-laurin, lauric acid mono-esters ofethylene glycol and diethylene glycol, and the like. They may be usedtogether with wetting. emulsifying, frothing, foaming, penetrating anddetergent agents such as the higher molecular weight alcohol or alkylsulphates, phosphates, pyrophosphates and tetraphosphates as, forexample, lauryl sodium sulphate, myristyl sodium pyrophosphate, cetylsodium tetraphosphate, octyl sodium sulphate, oleyl sodium sulphate, andthe. like;' higher molecular weight sulphonic acid derivatives such ascetyl sodium sulphonate and lauryl sodium sulphonate; sulpho-carboxylicacid esters of higher molecular weight alcohols such aslauryl sodiumsulphoacetate, dioctyl sodium sulpho-succinate, dilauryl potassiumsulpho-glutarate, lauryl monoethanolamine sulpho-acetate, and the like;sulphuric and suiphonic derivatives of condensation products ofalkylolamines and higher fatty acids; Turkey red oils; compounds of, thetype of isopropyl naphthalene sodium sulphonate, and other classes ofwetting agents.

The salts of the esters of the present invention may also be employed asintermediates in the preparation of other chemical compounds orderivatives, particularly those having emulsifying, wetting, frothing,sudsing, detergent and, in general, surface or interface modifyingproperties. Such derivatives include sulphates; sulphonates; phosphates,including pyrophosphates, triphosphates, orthophosphates,tetraphosphates and the like; sulpho-carboxylic acid amides, forexample, of such acids as sulphoacetic acid, sulphomaleic acid,sulpho-succinic acid, sulphobenzoic acids, sulpho-phthalic acids;quaternary ammonium and other onium derivatives, and the like.

If desired, the free esters may be recovered from the salts thereof inways known by those versed in the art, namely, by treating with a baseat low temperatures, for example, around 0-degrees C.

The term higher, as used herein and in the claims to describe carboxylicand fatty acids and the like, will be understood to mean at least eightcarbon atoms unless otherwise specifically stated.

While the invention has been described in detail, it is to be understoodthat the scope thereof is not to be limited other than is set forth inthe claims;

This application is a continuation-in-part of my prior application,Serial No. 364,032, filed November 2, 1940.

What I claim as new and desire to protect by Letters Patent of theUnited States is:

1. A method of preparing hydrochloride salts of higher molecular weightaliphatic carboxylic acid esters of alcohol non-tertiary amines,substantially free of amides of said carboxylic acids with said amines,which comprises reacting a higher molecular weight aliphatic carboxylicacid acyl chloride and a hydrochloride of an alcohol non-tertiary aminein the presence of an acid catalyst.

2. A method of preparing hydrochloride salts of fatty acid esters ofaliphatic hydroxy-alkyl secondary amines, substantially free of' amidesof said fatty acids with said amines, which com-.

prises reacting a, fatty acid acyl chloride containing from eight toeighteen carbon atoms and a hydrochloride of an aliphatic hydroxy-alkylsecondary amine in the presence of an acid catalyst at temperaturesbetween about 70 degrees C. and

diethanolamine hydrochloride in the presence of an acid catalyst.

4. A method of preparing hydrochloride salts of higher molecular weightfatty acid esters of diethanolamine, substantially free of amides ofdiethanolamine with said higher molecular weight fatty acids, whichcomprises reacting an acyl chloride of a higher molecular weight fattyacid and a substantially anhydrous hydrochloride of diethanolamine inthe presence of a sulphoacetic acid catalyst and at a, temperaturebetween about 70 degrees C. and 140 degrees C.

5. A method of preparing hydrochloride salts of higher molecular weightfatty acid esters of hydroxy-alkyl secondary amines, substantially freeof amides of said hydroxy-alkyl secondary amines with said highermolecular weight fatty acids, which comprises reacting substantiallyequi-molal quantities of an acyl chloride of a higher molecular weightfatty acid and a substantially anhydrous hydrochloride of anhydroxy-alkyl secondary amine in the presence of a small proportion ofphosphorous trichloride as a catalyst,

6. A method of preparing hydrohalide salts of carboxylic' acid esters ofalcohol non-tertiary amines, substantially free of amides of saidcarboxylic acids with said amines, which comprises reacting acarboxylicacid acyl, halide and a hydrohalide salt of an alcoholnon-tertiary amine in the presence of an acid catalyst.

7. A method of preparing hydrohalide salts of fatty acid esters ofaliphatic hydroxy-alkyl secondary amines," substantially free of amidesof said fatty acids with said amines, which comprises reacting a fattyacid acyl halide containing from eight to eighteen carbon atoms andahydrohalide of an aliphatic hydroxy-alkyl secondary amine in thepresence of an acid catalyst at temperatures'between about 70 degrees C.and about 130 degrees C. 4

8. A method of' preparing hydrohalide salts of higher molecular weightfatty acid esters of' di-' ethanolaminaj substantially free of amides ofdiethanolamine with said higher molecular weight fatty acids, whichcomprises reacting an acyl halide of, a higher molecular weight fattyacid and a hydrohalide salt of diethanolamine in the presence of an acidcatalyst.

9. A method of preparing hydrohalide salts of higher molecular weightfatty acid esters of diethanolamine, substantially free of amides ofdiethanolamine with said higher molecular weight fatty acids, whichcomprises reacting an acyl halide of a higher molecular Weight fattyacid and a substantially anhydrous hydrohalide of diethanolamine in thepresence of an acid catalyst and at a temperature between about 70degrees C. and 140 degrees C.

10. A method of preparing hydrohalide salts of higher molecular weightaliphatic carboxylic acid higher molecular weight aliphatic carboxylicacid esters of hydroxy-alkyl primary amines, substantially free ofamides of said carboxylic acids with said amines, which comprisesreacting a higher molecular'weight aliphatic carboxylic acid acyl halideand a hydrohalide salt of an hydroxy-alkyl primary amine in the presenceof an acid catalyst.

11. A method of preparing hydrochloride salts of higher molecular weightaliphatic carboxylic acid esters of hydroxy-alkyl primary amines,substantially free of amides of said carboxylic acids with said amines,which comprises reacting a acyl chloride and a hydrochloride of anhydroxyalkyl primary amine in the presence of an acid catalyst.

12. A method of preparing higher molecular weight fatty acid esters ofaliphatic hydroxyalkyl primary amines, substantially free of amides ofsaid fatty acids with said amines, which comprises reacting a fatty acidacyl chloride containing from eight to eighteen carbon atoms and asubstantially anhydrous hydrochloride of an allphatic hydroxy-alkylprimary amine in the presence of an acid catalyst at temperaturesbetween about 70 degrees C. and about 140 degrees C.

13. A method of preparing hydrohalide salts of higher molecular weightfatty acid esters of monoethanolamine, substantially free of amides ofmonoethanolamine with said higher molecular weight fatty acids. whichcomprises reacting an acyl halide of a higher molecular weight fattyacid and a hydrohalide salt of monoethanolamlne in the presence of anacid catalyst at a temperature below 100 degrees C. v

14. A method of preparing lauric acid esters of mcnoethanolamine,substantially free of lauric acid amides of monoethanolamine, whichcomprises reacting lauroyl chloride and monoethanolamine hydrochloridein the presence of a sulphoacetic acid catalyst.

15. A method of preparing higher molecular weight fatty acid esters ofmonoethanolamine, substantially free of amides of monoethanolamine withsaid higher molecular weight fatty acids, which comprises reacting anacyl chloride o1 a higher molecular weight fatty acid and asubstantially anhydrous hydrochloride of monoethanolamine in thepresence of a sulpho-acetic acid catalyst and at a temperature betweenabout 70 degrees C. and 140 degrees C.

16. The hydrochloride of fatty acid esters of hydroxy-ethyl ethylenediamine, substantially free from fatty acid amides of hydroxy-ethyl 10ethylene diamine, the fatty acid radical of sai esters comprisinglargely the lauric acid radical. 17. A method of preparing highermolecular weight fatty acid esters of hydroxy-alkyl primary amines,substantially free of amides of said bydroxy-alkyl primary amines withsaid higher molecular weight fatty acids, which comprises reactingsubstantially equi-molal quantities of an acyl chloride of a highermolecular weight fatty acid and a substantially anhydrous hydrochlorideof an hydroxy-alkyl primary amine'in the presence of a small proportionof phosphorous trichloride as a catalyst.

FRANK J. CAHN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date.

1,936,533 Albrecht Nov. 21, 1933 1,952,008 Bruson Mar. 20,1934 2,022,678Kritchevsky et al. Dec. 3, 1934 2,004,476 Barz June 11, 1935 2,058,013Henke et al Oct. 20, 1936 2,076,217 Albrecht Apr. 6, 1937 2,089,212Kritchevsky Aug. 10, 1937 2,151,788 Manersberger Mar. 28, 1939 2,169,515Albrecht Aug. 15, 1939 2,239,997 Epstein Apr. 29, 1941 2,280,830 JohnsonApr. 28, 1942 2,305,083 Jayne Dec. 15, 1942 2,354,320 Johnson July 25,1944 2,355,442 Jayne et al Aug. 8, 1944 FOREIGN PATENTS Number CountryDate 337,737 Great Britain Oct. 27, 1930 337,774 Great Britain Oct. 27,1930

